组成对MgO-ZrO2-CaO系合成料结构与性能的影响

以脱硅锆、白云石生料以及轻烧氧化镁为原料,研究了n(CaO)n(ZrO2)分别为0.8、0.9、1.0、1.1时对MgO-ZrO2-CaO合成料结构和性能的影响.结果发现当配料中n(CaO)n(ZrO2)＜1时,合成料中未发现有游离的ZrO2存在,且合成料中可生成CaZrO3和CaZr4O9两种锆酸钙相;随着配料中ZrO2含量的增加,合成料中方镁石和锆酸钙相呈现不同的分布特征;n(CaO)n(ZrO2)的提高有利于改善合成料的烧结性能;在合成料中,杂质成分主要以硅酸盐相存在,以孤岛状分布于锆酸钙颗粒的角隅之间,对合成料的烧结性能和高温性能没有太大影响.

Effect of chemical composition on microstructure and properties of MgO- ZrO2 -CaO system multiphase materials

MgO-ZrO 2-CaO system materials were synthesized with starting materials of light-fired magnesite, natural dolomite and zirconia.The effects of n (CaO)/ n (ZrO 2) (mole ratio) with the values of 0.8,0.9,1.0 and 1.1 of MgO-ZrO 2-CaO materials on microstructure,properties and phase composition of the materials were studied. It was found that:(1) When n (CaO)/ n (ZrO 2)<1,free ZrO 2 was not found,two calcium zirconates CaZrO 3 and CaZr 4O 9 were detected respectively in the materials;(2)With the increase of ZrO 2 addition,the periclase and calcium zirconates exhibited different distribution features in the materials;(3)The increase of n (CaO)/ n (ZrO 2) improved the sintering of the materials;(4)The impurities of Al 2O 3 and SiO 2 presented in the forms of silicate phase,which distributed on the corner of calcium zirconate grains,and they had not much effect on the sintering and high temperature properties of the materials.